Connectors used for connection of electrical circuits in motor vehicles are required to have high-degree waterproof sealing performance, so that a waterproof structure is employed. FIG. 1 is a cross sectional view showing one embodiment of a connector (waterproof connector) in which the waterproof structure is employed. In a female housing 3, a packing 1 is attached to an accommodating portion of a female metal terminal 7, and further, a portion through which an electric wire 9 connected to the female metal terminal 7 is led is sealed with a plug member 2. On the other hand, also in a male housing 4, a portion through which an electric wire 9 connected to a male metal terminal 8 is led is sealed with a plug member 2. Further, the packing 1 exhibits a ring shape, for example, as shown in FIG. 2.
An oil-bleeding NBR obtained by incorporating an aliphatic hydrocarbon oil into a butadiene-acrylonitrile copolymer (see patent document 1), an oil-bleeding silicone rubber material obtained by incorporating a silicone oil into a silicone rubber (see patent document 2) and the like are frequently used for sealing parts such as the packing 1 and the plug member 2. However, these rubber materials are thermoplastic, so that they are poor in recyclability. Accordingly, attention has recently given to thermoplastic resins having recyclability, and various studies have been made thereon.    [Patent Document 1] JP-A-61-21177    [Patent Document 2] JP-A-62-252457